alpha-N-acetylgalactosaminidase deficiency, a new lysosomal storage disorder

J Inherit Metab Dis. 1988;11(4):349-57. doi: 10.1007/BF01800424.

Abstract

A new lysosomal storage disease with autosomal recessive inheritance is described in two male siblings of 5 1/2 and 4 years of age. Clinical manifestations started after 9 months of age with neurological symptoms, followed by progressive psychomotor deterioration. Urinary oligosaccharide excretion was abnormal and showed a characteristic pattern on chromatography. Enzyme assays showed a profound deficiency of lysosomal alpha-N-acetylgalactosaminidase in cultured fibroblasts, leukocytes and plasma from the patients and reduced activity in material from the parents. The deficiency was demonstrated both with an artificial substrate and a natural one, the blood group A trisaccharide. Excessive intra-lysosomal storage of alpha-N-acetylgalactosamine-containing material was demonstrated in cultured fibroblasts from the patients, using the lectin from Helix pomatia which is specific for terminal alpha-N-acetylgalactosamine residues.

Publication types

  • Case Reports

MeSH terms

  • Acetylgalactosamine / metabolism
  • Cells, Cultured
  • Child, Preschool
  • Chromatography, Thin Layer
  • Fibroblasts / enzymology
  • Hexosaminidases / deficiency*
  • Histocytochemistry
  • Humans
  • Lectins
  • Leukocytes / enzymology
  • Lysosomes / enzymology*
  • Male
  • Oligosaccharides / urine
  • alpha-N-Acetylgalactosaminidase

Substances

  • Helix lectin
  • Lectins
  • Oligosaccharides
  • Hexosaminidases
  • NAGA protein, human
  • alpha-N-Acetylgalactosaminidase
  • Acetylgalactosamine